Furnace.



J. D. STEWART.

FURNAGB. K APPLICATION FILED JAN. 29, 19064 RENEWBD NOV. 23, 1906. 1,038,677D y Patented Sept. 17, 1912.

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WLUMBIA PLANDBRAPM C0'. WANIINGNN. D. C.

attoznmt Patented Sept. 17, 1912.

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CGLUMBIA PMMGIAPH C0.. WAIHINONN. D. C.

rafrnfr JAMES D. STEWART, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-TIIIRD 'IO OSCAR v0. LAUDIG AND ONE-THIRD TO WILLIAM F. DIGKSON, OF CHICAGO, ILLINOIS.

FURNAGE.

Specication of Letters Patent.V

Patented Sept. 17, 1912.

Application filed. January 29, 1906, Serial No. 298,416. Renewed November 23, 1906. Serial No. 344,788.

To all whom t may concern:

Be it known that I, JAMES D. STEWART, a subject of the King of England, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Furnaces, of which the following is a specification.

This invention relates to an appliance or device applicable to ,furnaces of any kind or make, the object being to provide a means of saving fuel, securing complete combustion, and preventing smoke. These objects are etfected by injecting hot air, steam, superheated oil and air or super-heated steam and oil into the furnace just above the bridge-wall, in a. manner and by means shown hereinafter.

Figure 1 is a longitudinal vertical section showing the device applied to the furnace of a steam boiler of the water-tube type,

such as the Stirling boiler. Fig. 2 is a ver tical cross section of the same. Fig. 3 is a longitudinal vertical section of a. modication. Fig. l is a view showing the vertical cross passage between the two series of passages.

Referring specifically to the drawings, 1() indicates the side walls of a boiler setting; 11 is the {ire-box or furnace; 11au is the arch or top of same; 12 is the ash-pit; 13 the bridge or bridge-wall, and 14 is the grate.

Inthe. preferable form of my invention, with a furnace such as shown in Figs. 1, 2 and 3, I arrange above the usual bridge a series of horizontal passages 132 formed by means of indurated tile or brick 13", preferably made of pressed magnesia, but lire brick may also be used. A vertical cross passage 13C is also arranged in the brick work to allow the compressed air, -or compressed air and oil, or steam, or steam and oil, to reach the several passages 13et from the mixing tubes 19.

16 is an air pipe leading from a tank 17, or other source of compressed air, and provided with a regulating valve 16a. 18 is a steam or oil pipe having a valve 18a. The air pipes are connected `at a T onk the outer end of the mixing tube or cylinder 19, and the steam pipe or oil pipe projects its nozzle within tube 19, as shown in Fig. 1.

In carrying out the invention, I preferably employ two or more mixing tubes 19, with one or more above the arch 11a. `Within the tubes 19 are placed iron chips 20, or

other scraps of metal, so as to provide means for the treatment of the air, the air and. oil, the steam, or the steam and oil, producing highly combustible gases .which pass into the space 13c through the vertical pipes 2l one or more of which .are connected to each tube or tubes 19. The stems or pipes 21 have jet openings 22, each being a longitudinal slot; or a series of small perforatlons may be employed. The vertical space 13CV forms what may be called a mixing chamber as air or other material from the pipes 21 is mixed in this space or chamber with the products of combustion, the passageways on each side of this mixing chamber being through heat nonconducting material. Y

When air, or air and oil, or steam, or

Vsteam and oil, are turned on they enter the tube 19 and are here vaporized into highly combustible gases which pass out of the Y openings in the stems 21 and come in contact with the unconsumed vapors or `smoke passing over the bridge-wall, thus providing oxygen forthe same which is immediately taken up and completes the combustion. The amount of heat generated is materially increased, and the smoke is consumed. rIhe lire brick-forming the tlues becomes white hot and retains the heat desirable for producing most effective expansion, mixture and combustion of the gases.

It will be noted that with this construction the gases from the fire enter the series of passages 13a, and that hotair or other material used is brought into contact with these gases back of the mouths of these passages. The incompletely combined gases, as it were, pass up from the fire and into the passages 13a where they are brought into contact with the heated surfaces by which the passages are formed," and after they have traveled in these passages for a portion of their length they are brought into contact with the hot air or other oxygen carrying material which then mixes with them and combines .with the unconsumed portions thereof t-he combination taking place in passages back of the point of introduction.

It will be seen that there is a heat nonconductingV device with at least two series of passageways with a mixing chamber between them. rIhe products of combustion pass through the first series and their temperature is raised. They are then passed through the mixing chamber and mixed with ducting ymaterial acts, as it Were, as a heat reservoir to hold the heat in place to be Vproperly applied to the products of com-V bustion.

Referring now to Figs. 1 andil 4 of the drawings, it will be noted that the mixing chamber divides the heat'non-conducting dejvice into two sections'and hence there is pro vided a grate with a heat non-conducting device back ofthe grate, a series of passages :through which' a portion of the products of combustion pass, and a second non-conduct Y' ing device with a series of passages back of said first device, a mixing chamber between said two series of passages and means forv comminglinga' heated gas with the products of combustion in the mixing chamber.

The passages 132l are, as it were, separated into sections by means of the cross passage or mixing chamber 13, the passages of each section communicating with this mixing chamber or cross passage 13G. Y 5

1, When air alone is used, the valve 18'l is closed. Instead of using a tank for the air, as shown in Fig. 1, I may simply take the air from the outside of the furnace, as shown in Fig. 3.

I claim: v Y

1'. A steam boiler furnace having an arch above the re box, and a bridge wall, a set of horizontal fire brick flues vin the space between the bridge-wall and the archand a vertical cross passage through said flues, and a series of mixing tubes exposed to the heat of the furnace and provided'with perforated discharge pipes located in said passage.

2. A steam boiler furnace having an arch e above the firebox thereof, and a bridge wall,

a plurality of mixing and vaporizing tubes extending lengthwise above the arch and projecting at their front ends through the front wall of the furnace, air and oil sup-j Vply pipes entering the front ends of the tubes, and perforated pipes which are co nnected to the rear ends of the tubes and which l, extend vdownwardly to the bridge wall, across the combustion space above said wall.

3. Arfurnace provided with a series of passages through which products of combustion from the furnace pass and separated into sections between which is formed a cross passage with which the passages of sectionsV being in alinement, means for introducing aiga's insaid cross passage between said sections so as to bringV it into contact with said products of combustion.

4. A furnace comprising a grate, a heat non-conducting device back of said grate having a/series of free substantiallyy hori# zontal passages through which products of combustion pass, a second non-conducting device, with a'series ofl substantially horizontal open passages, back of said first device, said heat non-conducting devicesVV forming two'separated heat storing kdevices with a mixing chamber between them with which both sets of passages communicatesaid mixing chamber formed between vertical faces of said, heat storingV device, and means for commingling aheated gas with said prodructs of combustion in said mixing chamber.

5. A furnace comprising a grate, a heat non-conducting device' back ofsaid grate having a series of free passages through whichproducts of combustion pass, a secf free passa-ges located'backof said A'first device, saidY heat non-conducting devices forming heat storing devices with a mixing chamber between them, a gas Y conducting, tube associated with said` mixing chamber and provided with openings through which the gas escapes so as to mingle with the products of combustion'while they are pass ing through the mixing chamber, the pass sages in the two non-conducting devices be`V ing in alinement, l

Y 6. Afurnace comprising` a grate, a heat non-conducting device back ofl said grate which products of combustion pass, a second non-conducting deviceV with a series of free passages located back of said rst device, the two devices forming heat storing devices ond non-conducting device with a series of Vhaving a series of free passages throughV with a mixing chamber between them, a gas .Y

.conducting tube associated with said mixingV chamber and provided with openings through which the gas escapes so vas to mingle with the products of combustion which are passing through the mixing chamber,

gles to said passages, the said passages in the heat storing devices vbeing V1n almement.

In testimony whereof I have signed my,

copies ot'this patent may be obtained for ve cents, each, by addressing the Commissioner of Patents,

Washington, D. G.

Athe gas from said tube injected at right an- 

